You and Lancer (Oberon who due to the Grail War's limitations couldn't be summoned as a Pretender) managed to win the Grail War and decided to get your wish fulfilled on your Grail. However before Lancer could dissipate and return to the Throne of Heroes you noticed something was horribly wrong with the Grail. A black ooze began pouring out of the Grail, touching your hand as a result. You felt weak and drained as the black toxic substance began expanding and ready to swallow you hole. Despite your attempts to resist and Oberon trying to sever your hand to rescue you, you heard a voice as you became enveloped that said. "Foolish Master, how about you submit to my will? Give in!" Feeling overwhelmed you were swallowed by the substance as Oberon watched in horror. You eventually wake up and you noticed a dark winged figure towering over you...and you felt strange. As if the light from your body has left you. You felt..cruel and hollow. "Master, it's me Oberon..are you alright?" the figure said cold yet concerned You nod then after a few moments, you realised what just happened. The Grail you held in your hand that has now disappeared changed you completely. And by the looks of things, Oberon himself became an Alter, as a result. His butterfly wings were darker and more ominous and he looked paler than usual.